Ministrator



Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE OSCAR JAECK, DECEASED, LATE OF REINACII, NEAR BASEL, I BY WOLFGANG JAECK, AD-

MINISTRATOR, OF BASEL, SWITZERLAND, AND FRITZ SCH'U'TZ, OF BASEL, SWITZER- LAND, ASSIGNORS TO THE FIRM F SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF

BASEL, SWITZERLAND PROCESS OF MAKING ACIDYL CELLULOSE No Drawing. Application filed June 27, 1929, Serial No. 374,268, and in Switzerland July 13, 1928.

Hitherto vegetable fibers have been immunizcd to directdyeing dyestuffs by means of acetic anhydride by treating the fibers for a long time with the aeylating agent, to which a catalyst has been added.

The present invention essentially simplifies this process, in that the textile to be immunized is first treated with a heavy metal salt of a strong acid, such as copper sulfate or cop per sulfate in the presence of a. very small amount of sulfuric acid, as is the case with crude copper sulfate, and then acylated by means of. an acylating mixture. The advantage of the invention resides in the substantial shortening of the acylating operation, which is reduced by the invention from several hours or days to a fraction of an hour.

The following example illustrates the invention 1 kilo of the usual prepared cotton is im;

pregnated with a solution of crude copper sulfate of 1 per cent. strength and then hydroextracted and dried. The goods are then immersed in 10 parts of acetic anhydride at the temperature of the water-bath. At the end of half-an-hour, the immunizing is complete, whereupon the goods are removed, hydro-extracted, rinsed and dried.

What we claim is 1. A process for immunizing vegetable fibers to direct dyeing dyestuffs by means of acetic anhydride, wherein the vegetable fiber is first treated with a solution of copper sulfate in the presence of a very small amount of sulfuric acid and then, after preliminary drying, acylated by means of an acylating agent.

2. A process for immunizing vegetable fibers to direct dyeing dyestuffs by means of acetic anhydride, wherein the ve etable fiber is first treated with a solution 0 copper sulfate in the presence at a very small amount of sulfuric acid and then, after preliminary gryng, acylated by means of acetic anhy- Deceased.

FRl TZ SCHUTZ. 

